Hyperbolic P-Y Model for Static and Cyclic Lateral Loading Derived From Full-Scale Lateral Load Testing in Cemented Loess Soils-Article

Article

Pdf Summary

The paper presents a hyperbolic p-y model for predicting the lateral response of piles in cemented soils with both cohesion and friction. The model was developed from full-scale static and cyclic lateral load tests on six instrumented drilled shafts in Kansas loess.<br /><br />The model describes soil resistance as a smooth function of pile displacement. Its response is governed by ultimate soil resistance, a reference displacement controlling how quickly resistance develops, and a correlation constant affecting behavior at small displacements. For cyclic loading, ultimate resistance is reduced according to the number of load cycles. The method also accounts for pile diameter: for the same soil strength, larger piles mobilize greater resistance and stiffness. Near the ground surface, ultimate resistance is reduced to represent passive-wedge effects.<br /><br />Cone penetration test tip resistance provided the strongest correlation for estimating soil strength; the authors calibrated the model parameters against the test-site data and provide a step-by-step procedure for generating p-y curves. Comparisons with measured shaft deflections and moments showed generally good agreement for static tests. Cyclic predictions also matched observations after accounting for differences in creep associated with the longer hold times during static testing.<br /><br />The authors conclude that the model is suitable for static and cyclic analyses of similar cemented soils and offers smooth curves that can improve numerical convergence. The proposed parameters are calibrated to the tested loess, however, and should be evaluated before application to other soil conditions.

Keywords

hyperbolic p-y model

lateral pile response

cemented soils

drilled shafts

Kansas loess

static and cyclic loading

pile deflection

ultimate soil resistance

cone penetration test

p-y curves